Fusion of body tissues for repairing tissues, including when closing surgical openings, as well as for creating new connections of tissue, such as an anastomosis for vascular bypass, has been an important concern of surgeons since surgical procedures were first used.
In vascular surgery, anastomoses need to be made to join vessels with other vessels or open volumes through which blood can flow. Such tissue connections should be made blood-tight, and be able to withstand the pressures and forces acting on them in vivo.
The creation of a fluid or blood-tight (hemostatic) and mechanically stable connection such as for an anastomosis takes considerable time, skill, and care and is prone to complications. Even slight misalignment, asymmetric tension, introduction of foreign material, or wrong tissue types may trigger bodily responses, such as thrombogenesis, coagulation, or scar formation, which may have a detrimental effect on the patency (i.e., the ability to let fluids pass) of a connection, or cause immediate or delayed leakage of vessels or vessel damage, later followed by dehiscence, pseudo aneurysm, or anastomotic aneurysm formation.
In most cases, tissue joints such as the ones required in an anastomosis are created when the surgeon sutures or staples tissues, such as vessel wall tissues, together. Tissue soldering, tissue welding, and the use of adhesives have also been discussed, but the first two methods are not widely used, while adhesives are generally only used in combination with sutures, clips, or mechanical closures.
A common concern associated with the use of adhesives, especially when connecting blood vessels, is that the adhesive may enter the bloodstream leading to blockage and other complications. In addition, using adhesives alone to join body tissues can result in mechanically unsafe connections or connections with insufficient patency. The tissues to be joined can be under a different tension during surgery than in vivo, or can be subject to varying tensions, which can result in the weakening or breaking of an adhesive bond between the tissues or a change in the form of a connection. Although methods of using adhesives to connect a graft to an unoccluded recipient vessel were described decades ago (see, U.S. Pat. No. 3,805,793 to Wright, which was issued in 1974), adhesives are generally not used by themselves in surgical procedures for the reasons stated above, despite the apparent advantages that adhesives seem to offer, in particular, ease of application.
In many clinical applications, it is advantageous to perform anastomosis without occluding the recipient vessel. This becomes particularly important when the recipient vessel involved performs a vital function. In generally sensitive or critical organs such as the brain, occluding a recipient vessel even temporarily is often disadvantageous. A technique commonly referred to as the ELANA (Excimer Laser Assisted Nonocclusive Anastomosis) technique, is used in clinical practice to create an anastomosis without occluding the recipient vessel (see also, U.S. Pat. No. 5,964,750 (Tulleken et al.)). This technique is, e.g., used by neurosurgeons in bypass surgery. After attaching an implantable ring around a distal portion of the graft vessel, the end of the graft vessel is folded back over the ring creating an orifice that is reinforced by this ring. This reinforced orifice of the graft vessel is attached to the wall of the recipient vessel of the patient. This attachment is generally performed by suturing the graft vessel to the recipient vessel via eight sutures approximately. Depending on the skill of the surgeon and the conditions found in the patient, the attachment will take generally anywhere from half an hour to one hour or more. A laser catheter is then inserted into the graft vessel to create an opening between the graft and recipient vessel. During the entire procedure, blood will continue to flow within the recipient vessel, avoiding the temporary shut off of the bloodstream associated with many other anastomosis methods.
There exists a need in the art for an improved method for attaching body vessels to each other, as well as for an improved anastomostic surgery aid for forming connections between body vessels. Therefore, the purpose of this invention is to fulfill this andor other needs in the art which will become apparent to the skilled artisan once given the following disclosure.